Air conditioning



July 16, 1940. w. GOODMAN AIR CONDITIONING Original Filed April 15, 19356 Sheets-Sheet 2 5 7'5 14M WAP RECEIVER July 16, 1940. w. GOODMAN2,207,728

AIR CONDITIONING Original Filed April 15, 1935 6 Sheets-Sheet 5COMP/P5509 10 COMPRESSOR 3Z1 1:5 .11

COMPRESSOR 5g 60C lhz/enfor:

July 16, 19 w. GOODMAN AIR CONDITIONING Original Filed April 15, 1935 6Sheets-Sheet 4 TEMPE Pl 71/195 PL'SPGM/Vl DEV/CE LOW PRAISE IRE 4 6 5 66 5 m 5 5 f R P m We 5 ZEN/027ml":

July 16, 1940- w. GOODMAN AIR CONDITIONING Original Filed April 15, 19356 Sheets-Shea July 16, 1940- w. GOODMAN AIR CONDITIONING Original FiledApril 15, 1955 6 Sheets-Sheet 6- JZW/en far:

I I l I IIL Patented July 16, 1940 UNITED STATES PATENT orricr.

Application April 15, 1935, Serial No. 16,306 Renewed April 10, 1940 25Claims.

The primary object of my invention is to so operate the refrigeratingmechanism of an air conditioning system that refrigeration of airsupplied to a railway car or the like and the accumulation of energy forsubsequent refrigeration of air may be effected simultaneously or sothat refrigeration of air or accumulation of energy may be effectedindependently or so that refrigeration of the air may be effected byutilizing accumulated energy.

Another object of my invention is to utilize substantially the sameequipment for refrigerating or heating air supplied to a railway car orthe like. 1

Other objects are to compactly arrange the air conditioning system toenable installation thereof in the available space in a railway car orthe like and to utilize substantially the same equipment whenrefrigeration of air supplied to the car is effected by operation of acompressorcondenser-evaporator refrigerating mechanism or by utilizationof accumulated energy.

Still further objects of the invention are to utilize the availableenergy in the axle, or other part of a railway car or the like that isdriven when the car is in motion, for operating the compressor of acompressor-condenser-evaporator refrigerating mechanism and therebyrefrigerate air supplied to the car and accumulate energy while the caris in motion, and to utilize the accumulated energy and continuerefrigeration when energy for operating the compressor is not available,and to automatically regulate such operation of the refrigeratingmechanism.

Further objects are toenable alteration of the operation of an airconditioning system from air cooling to air heating or from air heatingto air cooling and to insure proper operation of the system upon suchalteration of the operation; to automatically control the degree oftemperature change eiiected in air suppliedto a railway car or the like;to automatically control the temperature of the air in a railway car orthe like; and to control the accumulation of energy and thereby enableefficient operation of the refrigerating mechanism.

More specific objects of the invention are to provide a heat exchangerin the air supply passage of a railway passenger car or the like and toutilize this heat exchanger as an evaporator when air flowing throughthe passage is to be refrigerated and to utilize this heat exchanger asa heater when the air flowing through said passage is to be heated; toenable a railway passenger car or the like to be air conditioned priorto the start of a period of use thereof; to enable, operation of arefrigerating mechanismwhen the car is at rest by utilizing ice tocondense vaporized refrigerant and to produce ice by operation of therefrigerating mechanism when the car is in motion; to mechanicallycirculate a refrigerant to effect direct expansion in the heat exchangerwhen ice is employed to condense vaporized refrigerant; and to preventthe passage of liquid refrigerant to the compressor oi. acompressor-condenser evaporator refrigeratii'ui mechanism.

A still further object is to provide a novel speed responsive device forregulating operation of the air conditioning system when the railway caror the like is in operation.

Other and further objects will appear in the following descriptionwherein reference is made to the accompanying drawings in which Fig. 1is a view illustrating an air refrigerating and heating system for arailway car or the like;

Fig. 2 is a fragmentary View, similar to Fig. 1, showing a modified formof heating means;

Fig. 3 is a fragmentary side elevation, partly in section, illustratingthe manner in which the compressor of a compressor-condenser-evapora torrefrigerating mechanism may be connected to the axle of a railway car;

Fig. i is another fragmentary view illustrating a still further modifiedform of heating means;

Fig. 5 is a fragmentary view of a multi-cylinder compressor connectedfor use in the system shown in Fig. 1;

Fig. 6 is a sectional detail View taken sub stantially on the line Ka-ii on Fig. 5;

Fig. 7 is a view of a multiple effect com pressor connected for use inthe system shown in Hg. 1;

Fig. 8 is a sectional detail view taken substantially on the line 8-8 onFig. 7;

Fig. 9 is a view of a multi-cylinder compressor connected for use in thesystem shown in Fig. 2;

Fig. 10 is a view of a multi-cylinder compressor connected for use inthe system shown in Fig. 4;

Fig. 11 is a view of a multiple effect compressor connected for use inthe system shown in Fig. 2;

Fig. 12 is a view of a multiple eifect compressor connected for use inthe system shown in Fig. 4;

Fig. 13 is a view illustrating another form of my novel airrefrigerating and heating system;

Fig. 14 is a view of a multi-cylinder compressor connected for use inthe system shown in Fig. 9;

Fig. 15 is a view of a multiple effect compressor connected for use inthe system shown in Fig. 9;

Fig. 16 is an elevational detail view, partly in section, of a three-wayvalve employed in the systems shown in Figs. 9, 10 and 11;

Fig. 17 is a wiring diagram of a control system for the airrefrigerating and heating system shown in Fig. 1; and

Fig. 18 is a vertical sectional detail view of a preferred form of speedresponsive device employed in my invention. I

My invention is particularly adaptable for air conditioning a railwaycar 28 (Fig. 3) or the like. The compressor C of thecompressor-condenserevaporator refrigerating mechanism of my airconditioning system is preferably supported below the car floor bysuitable brackets 2|. The drive shaft 22 of the compressor is connectedto a speed control device 23 of any desired type operable to limit themaximum speed at which the compressor C can be operated or to operatethe compressor at a constant speed. A shaft 24 connects the speedcontrol device to a magnetic clutch 25 or Y similar means for connectingthe shaft 24 to the shaft 26- that is connected to an axle 21 or otherpart of the car operated when the car is in motion. When the magneticclutch 25 is engaged and the car is in motion power is transmitted fromthe axle 21 through shaft 26 and clutch 25 to shaft 24 and the speedcontrol device 23 to operate the drive shaft 22 of the compressor 0. Anarrangement such as this or any other suitable means may be employed foroperating the compressor C.

The form of the invention shown in Fig. 1 includes acompressor-condenser-evaporator refrigerating mechanism having acompressor C2 which is operated in the manner previously described. Theoutlet pipe 28 leads from the high pressure side of the compressor to acondenser 29 which, like the compressor C2, is suitably supported belowthe car floor. A valve 30 is provided in the outlet pipe 3| of thecondenser 29 and controls flow through this pipe. The valve 30, likeother valves illustrated herein, is of the solenoid type although it isto be understood that pneumatically or hydraulically operated valves, orvalves otherwise electrically operated, could be substituted for thesolenoid operated valves without departing from the purview of myinvention. Moreover, the valves could be used as pilot valves to controlthe operation of power operated valves located in the positions whereatvalves are located in this disclosure of the invention.

A receiver 3!, preferably insulated, is suitably supported below the carfloor. A pipe 32 leads from a T-fitting 33, to which the pipe 3| isconnected, to the receiver. A pipe 34 leads from the receiver 3! to aT-fitting 35. A pipe 36 leads from the T-fitting to a pump 31 that issuitably supported below the car floor. In order to insure self-priming,the intake of the pump may be located in or below the liquid level to bemaintained in the receiver 3|. Preferably the pump 31 is a centrifugalor bellows pump or other type through which there may be unimpeded flowwhen the pump is at rest. The pump 31 is operated by the motor 38.

A pipe 39 leads from the pump 31 to a T-fitting 40 and has a solenoidvalve 4! therein adjacent the fitting 49. A pipe 42 leads from theT-fltting 40 to an expansion valve 43 of approved form and preferablyhas a strainer 44 and a dehydrator 45 therein. A pipe 46 leads from theexpansion valve 43 to a T-fltting 41 and a pipe 48 leads from to providea by-pass about the expansion valve 43 and has a solenoid valve 5|therein.

A pipe 52 leads from the heat exchanger 48 to a back pressure valve 53,to be described more fully hereinafter. A temperature responsive device.4 is provided on the pipe 52 for controlling the expansion valve 43 inconnection with the pressure of evaporation in the heat exchanger 49.

A pipe 55 leads from the back pressure valve 53 to a T-fitting 56. Inthe preferred arrangement of my invention the T-fltting 56 is locatedbelow the car floor line whilethat part 01' the pipe 39 adjacent theT-fltting 48 and the T-fltting 40, pipe 42, expansion valve 43,T-fltting 41 and pipe 58 as well as the heatexchanger 49, pipe 52,temperature responsive device 54 and back pressure valve 53 are mountedabove thecar floor- However, the entire system may be located above orbelow the car door or otherwise without departing from the ambit of myinvention. The heat exchanger 49 is mounted in the air supply passageleading to the railway passenger car or the like.

A pipe 51 leads from the T-fltting 56 to a T-fltting 58 and has asolenoid valve 59 therein. A pipe 60 leads from the T-fltting 58 to thestrainer 6| and a pipe 62 leads to the suction or low pres- I sure sideof the compressor C2.

The mechanism thus far described will refrigerate air flowing over theheat exchanger 49 when the car is in operation above a predeterminedspeed, as will be explained more fully hereinafter, but when the car isoperating below the predetermined speed or when the car is at rest othermeans are provided for refrigerating air flowing over the heat exchanger49.

An ice tank 63 is mounted below the car floor and includes a water inletpipe 64 having a manually operated valve 65 therein so that when thevalve 65 is opened water may flow into the tank 63. The tank 63 is alsoprovided with an accessible door D through which cracked ice or the likemay be introduced into the tank for a purpose to be explained. Waterintroducedinto the tank 63 is to be frozen and to allow for expansionupon freezing the tank 63 is not completely filled with water, and tothis end a suitable overflow device such as the steam float trap 66 isprovided near the top of the tank so that when an excessive quantity ofwater is introduced into the tank it will flow out through the exhaust61 of the trap 66. It is to be understood, of course, that a steambucket trap or other suitable device could be used in place of the steamfloat trap 66.

A heat exchanger 68 is provided in the tank 63. A pipe 69 leads from theheat exchanger 68 to the T-fitting 58 and has a solenoid valve 19therein. Connection of the pipe 69 to the fitting 58 provides a returnfor refrigerant supplied to the heat exchanger 68. Herein the heattransfer fluid is referred to as a refrigerant inasmuch as therefrigerating system of my invention is claimed herein, but it is to beunderstood that this term is used in a generic sense where the heatexchanger 49 is employed to heat air flowing into the car, and thereforethe term refrigerant is employed herein as meaning a thermic fluid, thatis, a fluid employed to transfer heat from one place to another.

Refrigerant is supplied to the heat exchanger 68 through a pipe 1i thatleads from the T-fitting 35 to a T-fitting 12. The pipe 1i has asolenoid valve 13 therein. From the fitting 12 refrigerant flows throughpipe 14 to the expansion valve 15.

'15 refrigerant flows to the The pipe 14 preferably has a strainer 18and a dehydrator 11 therein. From the expansion valve heat exchanger 68through pipe 18, T-fltting 19 and pipe 80. A pipe 8| extends between theT-flttings 12 and 19 and provides a by-pass about the expansion valve 15and has a solenoid valve 82 therein. A temperature responsive device 83is provided on the pipe 69 adjacent the evaporator 88 and controlsoperation of the expansion valve 15 in connection with the back pressurein the heat exchanger 58. A thermostat 84 is provided in the tank 89 tocontrol the freezing of water in said tank.

A pipe 85 connects the T-fltting 33 to the T-fitting 58 and has asolenoid valve 86 therein. The utility of this arrangement will bedescribed more fully hereinafter.

All of the valves employed to control the flow of refrigerant in thesystems illustrated and described herein are normally closed and must beopened to effect operation of the systems.

The air conditioning system shown in Fig. 1 is also adaptable forheating air flowing over the .heat exchanger 49. In order to supply heatto the system, a heating coil 81 is provided in the receiver 3I and theinlet 88 thereof has a motor operated valve 89 therein to control theflow of steam or other heating medium into the coil 81. The valve 89 maybe other than motor operated and is responsive to the degree of heatingrequired for, as will be explained, it is preferably under control of athermostat. The outlet 90 of the coil 81 extends exteriorly'of thereceiver 3| and depends downwardly to permit the discharge of water orthe like from the coil 81. The pipe 90 has a trap 9I or the like thereinto prevent premature escape of steam or other heating medium from thecoil 87.

So long as refrigeration is to be effected in the heat exchanger 49 orthe evaporator 88 and the car or the like on which the system is mountedis in motion, the compressor C2 is to be operated unless the speed ofthe car falls below that which will efficiently operate the compressor.However, when the car is at rest or the speed thereof falls below thatwhich will efficiently operate the compressor G2, I disconnect thecompressor from the axle 21 or other part effecting operation thereof,and this can be effectively accomplished by providing a control deviceresponsive to thespeed of the car. Moreover, I control the refrigeratingmechanism by a speed responsive device so that refrigeration may beeffected by the compressor-condenser-evaporator refrigerating mechanismwhen the car is in motion or by accumulated energy when the car is atrest.

One form of device responsive to the speed of the car which may beadvantageously used herein is illustrated in Fig. 18 and is generallyindicated by S. The speed responsive device S includes a housing 92. Aboss 93 is provided at the top of the housing 92 and is hingedlyconnected to a bracket 94 depending from the car floor, and this hingedmounting is such that the housing 92 is free to swing parallel to thelongitudinal extent of the car.

A rotor 95 of insulating material in the housing 92 has a boss 96 at theupper'end thereof in which there is an opening receiving a centrallylocated guiding pin 91 depending from the top of the housing 92. Abearing 98 at the bottom of the rotor 95 rides on a bearing 99 and isconnected to a flexible shaft I and, as best shown in Fig. 3, theflexible shaft I00 is connected to the axle 21 so that it will be drivenupon movement of the car although the shaft I00, like the shaft 28, maybe connected to any other part that is operated when the car is inmotion.

The rotor 95 is in the form of a closed cup and mercury or other heavyliquid is stored therein. Conductor rings IOI, I02 and I03 are providedat vertically spaced intervals in the upright wall of the rotor 95. Theconductor rings are arranged to be disclosed on both the inner and outerperipheries of the rotor 95. While I have shown three conductor rings itis to be understood that any number greater than two and which can beaccommodated in spaced relation in the wall of the rotor may be providedwithout departing from the purview of myinvention.

A block I04 of insulating material is mounted on the housing 92 andcarries a spring contact arm I that bears against the outer periphery ofthe conductor ring I03. Another block I08 of insulating material ismounted on the housing 92 and carries a spring contact strip I 01 thatbears on the outer periphery of the conductor ring I02. Still anotherblock I08 of insulating material is mounted on the housing 92 andcarries a contact strip I09 that bears on the outer periphery of theconductor ring IOI. Conductors I I0, I I I and I I2 are respectivelyconnected to the contacts I05, I01 and I09. A condenser H3 is providedbetween the contacts I05 and I01 and a condenser H4 is provided betweenthe contacts I01 and I09 to prevent arcing, as will be explained.

When the rotor 95 is at rest the mercury or other heavy liquid collectsat the bottom thereof. However, when the rotor 95 is set in operationcentrifugal force causes the mercury to ascend the vertical wall of therotor 95 and the extent of ascent is proportionate to the speed ofrotation of the rotor. Thus when the rotor is rotating rather slowly themercury so ascends that circuit is established between the conductorrings Iili and I02 but when the rotor 95 is rotating at a relativelyhigh speed, circuit is established between the conductor ring'l03 andthe conductor rings Iill and I 02. It will thus be seen that as thespeed of rotation of the rotor 95 increases the mercury proportionatelyascends the vertical wall of the rotor 95 and selectively engages thevertically spaced conductor rings provided in the vertical wall of therotor. Likewise, as the speed of the rotor decreases the mercurydescends the vertical wall of the rotor 95 and successively disengagesthe vertically spaced conductor rings. The condensers M3 and H6. preventarcing that might be incident to bringing the conductor rings into ortaking the conductor rings out of circuit as the mercury ascends ordescends the vertical wall of the rotor 95;.

The air refrigerating and heating systems of I my invention are capableof operating under a number of different conditions which may becharacterized as:

Condition Air-When the car is to be cooled when initially placed inservice.

Condition B.-When the car is in motion and refrigerant is to be suppliedonly to the heat exchanger 99 to refrigerate air being supplied to thecar.

Condition C.-When refrigerant is to be supplied not only to the heatexchanger 49 to refrigerate air being supplied to the car but also tothe heat exchanger 68 to freeze water in the tank 63 and therebyaccumulate energy.

Condition D.When refrigerant is to be supplied only to the heatexchanger 58 as when it is and operation of the refrigerating mechanismis;

denser-evaporator refrigerating mechanism has:

been operating to supply refrigerant to the heat exchanger 49 torefrigerate air flowing over this heat exchanger (as under Conditions Band C)- interrupted but refrigeration of air flowing over the heatexchanger 49 is to be continued.

Condition F.--When air being supplied to the car past the heat exchanger49 is to be heated. Here, the mechanism operates in the same manher whenthe car is initiallyplaced in service as it does when it is in serviceeither running or at rest.

Condition G.-'I'hls is a special condition which 25 all of the systemswhich I have disclosed are not capable of performing and which isparticularly useful when a railway car or the like is operated to passfrom a cold climateinto a warm climate and wherein heating of the car isto be carried out but at the same time energy is to be accumulated byfreezing water in the tank 93.

The-system disclosed in Fig. 1 is operated in the" following manner toaccomplish all of the foregoing conditions except the Condition G ofwhich it is not capable. I

v I Condition A--.i ig. 1

When a car is initially placed in service and it is to be cooled, asupply of cracked'ice or other refrigerating medium is introduced intothe tank 63 through the door D and the system is arranged as follows:The valve 4| is opened to permit fiow of liquid refrigerant through theexand pipe 36. However, when the heat exchanger will act as a condenserand the, vaporized re--.

frigerant will therefore begliquefled as it flows through this heatexchanger "and the liquid refrigerant flows through pipe 89 tofittlng'IB. In order to by-pass the-liquid refrigerant above theexpansion valve 15,-the valve 82 is opened and the liquid refrigerantflows from the'fitting 19 through pipe 8| to fitting I2 from whence itflows through pipe H pastthe opened valve 13 to the fitting 35. Themotor 38 will at this time be operating the pump 31 and liquidrefrigerant flowing to the fitting 35 will be drawn through the pipe 36into the pump 31 to be forced through the pipe 39 past opened valve M tothe expansion valve 43. The motor 38-and the valve 82 are controlled incommon for the motor is not operated unless the valve is open.

If more refrigerant is condensed in the heat exchanger 68 than isrequired by the heat exchanger 49, all of the liquid refrigerant willnot flow through the pipe 36 to thepump' 31 but a part will fiow fromthe fitting 35 through the pipe 34 into the receiver 3|. Likewise, ifsufficient refrigerant is not condensed in the heat exchanger 69, liquidrefrigerant'willbe drawn from the receiver 3i through pipe 34, fitting35 49 is serving as an evaporator and the heat exchanger 98 is servingas a condenser. the quanrefrigerant evaporated in the heat ex- 88 willtend to equalize. Thus, equilibrium in the action of the heat exchangerswill-be established and any excess or deficiency of refrigerant will bemomentary and only-incident to the initiation of this operation. As theheat exchanger 68 operat'esv as a condenser, the ice in the tank 63 willmelt and the resulting water should properly fill the tank 63. However,any deficiency in water in the tank 63 may be supplied by manuallyopening the valve 65. Any excess water in the tank 63 willbe dischargedthrough the overflow'device 66, as explained. I

Thevalves 30, 5|, 86 and 89 are closed under this condition ofoperation.

Condition B-Fig. 1

When the compressor-condenser-evaporator refrigerating mechanism isto beoperated to supply refrigerant only to the heat exchanger 49, the valveM is opened while the valve 5| is closed. The valve 59 is opened as wellas the valve 39. The valves 19 and 88 are closed as well as the valvesI3 and 82 and, since steam is not to be supplied to the coil 81 when thesystem is operating to supply refrigerant either to the heat exchanger49 or the heat exchanger 68,

"the valve 89 is closed.

With the valves arranged in this manner refrigerant may flow from thereceiver 3| through the valve 41 and past the expansion valve 43,

which operates in the usual manner to maintain a supply of refrigerantto the heat exchanger 49 so long as air flowing over the heat exchangeris to be refrigerated. Since the valve 59 is open, the refrigerant mayreturn to the suction side of the compressor C2 so long as it isoperating and refrigerant forced from the compressor through thecondenser 29 may flow through the opened valve 39 back to the receiver3!.

Condition C-Fig. 1

When the compressor-condenser-evaporator refrigerating mechanism is tobe operated tonot only supply refrigerant to the heat exchanger 49 butalso to the heat exchanger 68 so as to freeze water in the tank 53, thevalves 13 and 19 are opened in addition'to the valves which are openedunder Condition B, the other valves closed under Condition 13, remainingclosed. Therefore, refrigerant may also flow past the valve 13 and theexpansion valve which functions' in the manner well understood tomaintain a supply of liquid refrigerant in the heat exchanger 68 so longas water in the tank 63 is to be frozen or ice is to be maintained inthe tank 53, and vapor refrigerant from the heat exchanger 68 may fiowpast the open valve 10 to be returned to the compressor, condenser andreceiver.

Operation of back pressure valve 53.

When liquid refrigerant is being supplied to both the heat exchanger 49and the heat exchanger 68, the back pressure valve 53 is operative forinasmuch as the heat exchanger 49. is refrigerating air, which is notchilled to a low temperature, it is operating at a. higher temperatureand consequently a higher saturation pressure than the heat exchanger 68which is operated at a much lower temperature than the heat exchanger 49since it is operating to freeze water in the tank 53 and to maintain iceso produced. Therefore. the saturation pressure in the heat exchanger 99is much lower than that in the heat exchanger 49. The suction of thecompressor to which these heat exchangers are connected would tend toequalize the saturation pressure in these heat exchangers and it is thefunction of the back pressure valve 53 to avoid this condition. Thisback pressure valve 53 so functions that a saturation pressurecorresponding to the temperature of refrigeration desired to bemaintained in the heat exchanger 49 is set up and maintained and ahigher saturation pressure is therefore maintained in the heat exchanger49 than is maintained in the heat exchanger 68. This higher pressureprevents the temperature of refrigeration in the heat exchanger 49 fromfalling to or below a temperature whereat undesirable frosting on theexterior surface of the heat exchanger 49 will occur.

Condition DFig. 1

When refrigerant is to be supplied to the heat exchanger 68 and not tothe heat exchanger 49, the valves are arranged as follows: The valve 4|is closed as well as the valve and this shuts off the supply of liquidrefrigerant to the heat exchanger 49. However, since it will beadvantageous to evacuate the heat exchanger 49, the valve 59 is keptopen so that upon operation of the compressor 02 any refrigerantremaining in the heat exchanger 49 will be returned to the condenser andreceiver. The valve 39 is opened to permit flow of the refrigerant fromthe condenser to the receiver. The valve l3 is kept open so thatrefrigerant may fiow past the expansion valve 15 as before and the valve82 is kept closed. The valve i9 is opened so that vaporized refrigerantmay be withdrawn from the heat exchanger 68 and returned to thecondenser and receiver. The valves 86 and 99 remain closed.

Condition E-J'ig. 1

Condition F-Fig. 1

When the heat exchanger 49 is to function as a heater, the system isarranged as follows: The valve 99 is operated by a thermostat responsiveto the temperature of air leaving the heat exchanger 49 so that when thetemperature of air falls the valve 99 is opened to admit steam into thecoil 81 and when the temperature of air rises the valve 89 is closed toshut off steam to the coil 81. Steam supplied to the coil 97 vap orizesrefrigerant in the receiver 3| and thevaporized refrigerant flowsthrough pipe 32 to fitting 33. The valve 39 is closed at this time toprevent fiow of the vapor refrigerant into the con denser 29 but thevalve 86 is open so that the heated vapor refrigerant may flow throughthe pipe 85 to the fitting 56. From the fitting 56 the refrigerant flowsthrough pipe 55 to back pressure valve 53. Inasmuch as the refrigerantin the receiver 3| may be heated by the steam flowing through the coil91 to a temperature closely approximating the. temperature of the steam,a relatively high saturation pressure is established in the receiver 3|when steam flows through coil -81. This pressure is always suflicientlyhigh to' open the back pressure valve 53 wide and so long as therelatively high pressure refrigerant is supplied through'the pipe 55 thevalve 53 will remain open. From the valve 53 the refrigerant flowsthrough pipe 52 into heat exchanger 49 from whence it flows through pipe48 to fitting 41 and the valve 5| is opened at this time so that therefrigerant is by-passed about the expansion valve 43 through the pipe59 to the fitting 40 from whencethe refrigerant flows through pipe 39,for at this time the valve 4| will be open, and from pipe 39 therefrigerantfiows through pump 31, fitting 35 and pipe 34 back into thereceiver 3|. The valves 13 and 82 are kept closed at this time toprevent the flow of heated refrigerant into the heat exchanger 68.

Likewise, the valves 59 and 19 are kept closed and closing of the valve59 prevents the heated refrigerant from collecting in the pipe '69,strainer 6| and pipe 62. This is important for these parts are exposedbelow the car, and when the heat exchanger 49 is functioning as a heaterthe temperature about the pipe 69, strainer 6| and pipe 62 may be lowenough to condense any refrigerant collected therein with the resultthat if the compressor C2 was set in operation with liquid in the pipe62, for example, serious damage to the compressor might result.

The control of the system shown in Fig. 1 may be effected in a number ofways to establish the various operating conditions and, of course, itmay be done manually but it is advantageous to perform this controlautomatically. One form of automatic control is shown in Fig. 17 andthis is electrical. While the disclosure is such that the various valvesare electrically operated to effect the desired set-ups of the system,the valves shown in Fig. 1'7 could control the flow of fiuid to thevalves shown in Fig. l in which instance the valves in Fig. 17 wouldserve as pilot valves and the valves shown in Fig. 1 would either bepneumatically or hydraulically operated. The control system shown inFig. 17 is but an illustrative arrangement and other systems may be usedwithout departing from the purview of my invention.

Power for operating the control shown in Fig. 17 is supplied through theline wires l l5 and H6 which may be respectively connected to thedistributing wires ill and M8 by the switch H9,

and when the switch H9 is open the entire control is renderedinoperative.

When the switch H9 is closed current is supplied through the conductorl2!) to one terminal of a manual selector switch l2l. This manualselector switch may be arranged in an ofi position or it may be throwninto position wherein the control system is arranged to control coolingof air flowing over the heat exchanger 99 or into a position to controlheating of air flowing over this heat exchanger. When air flowing overthe heat exchanger 49 is to be cooled or refrigerated, the blade N2 ofthe switch l2| is engaged with the terminal l23. A conductor |24connects the terminal I23 with the terminal |24a in the thermostat l25that is located at a selected position in the car. When the temperatureof air affecting the thermostat |25 rises above a predetermined maximum,circuit is closed through this thermostat to the terminal |26. Aconductor I2! leads from the terminal I26 to the terminal I28. If thecar is at rest at this time and the tank 63 is filled with ice and lowtemperature water, the operation of the device is as follows:

Current will fiow from the terminal I28 through the conductor are to oneterminal of the winding I39 of the valve M relay. From the otherterminal of the winding lit current flows through.

the conductor l3l to the distributing wire H8. The winding I is thusenergized and the armature H32 thereof is attracted whereupon thecontact M3 closes the circuit between the terminals lid and W5. Aconductor l36 connects the terminal E36 with the distributing wire I H.A conductor l3? leads from terminal l to one terminal of the winding l38of the solenoid oi. the valve ti and from the other terminal of thiswinding current flows through the conductor lit to the distributing wirelit and in this manner the valve ill is opened.

When the armature i3? is attracted, the contact Mil closes circuitbetween the terminals lll and M32. A conductor M3 connects the terminalll with the conductor lit. A conductor ltd leads from the terminal M2 toa terminal I65 in the valve it relay. A conductor ltE leads from theterminal M5 to one terminal of the winding Ml of the solenoid of thevalve 59 and a conductor llt connects the other terminal of. thiswinding to the distributing wire H8. Therefore the solenoid of valve 53is energized and this valve is opened along with valve ll.

Inasmuch as the heat exchanger 68 is to serve as a condenser, the pump3i must be set in operation and this is brought about by starting themotor 38 simultaneously with the just described opening of the valves lland 59. To this end a conductor M9 is connected to the terminal E28 andthis conductor leads to one end of the winding l5il' of the pump relay,the other end of said winding being connected to a terminal liila by aconductor lbl. The terminal ltla is provided in the centrifugal switchrelay in which there is another terminal l5lb and circuit between theseterminals is normally closed by a contact l5lc in the relay. Theterminal Hill) is connected to wire l3! by a conductor l5ld. Thus whenthe thermostat I25 is closed, the winding lfifi -is energized and thearmature I52 is attracted, The armature 852 carries a contact l53 thatcloses circuit between terminals l'avt and l55 when the armature l52 isattracted and simultaneously with the closing of circuit betweenterminals l5l and l55 the contact l56 on armature I52 closes circuitbetween terminals l5? and i583. A conductor I59 connects the terminaluse with the distributing wire ill and a conductor Hill connects theterminal i5? with the distributing wire H8. A conductor ltl leads to aterminal l6! from the terminal l55. A conductor l83 leads from terminall58 to a terminal Hit. A wire E leads from terminal it? to one pole ofthe motor 38 and a conductor l66 leads from the other pole of the motorto terminal ltd. Thus when circuit is closed between the contacts ltdand IE5 and I5? and I58, the motor 38 is set in operation.

As has been explained, at the time the motor 38 is set in operation tocirculate refrigerant condensed in the heat exchanger 68 the valve 82should be opened to by-pass the condensed refrigerant about theexpansion valve 15 and therefore the winding of the solenoid of thevalve 82 is connected to the same terminals as those to which the motor38 is connected. Thus a conductor lB'l leads from the terminal l62 toone end of the winding of the solenoid of the valve 82 and a conductorl68 leads from the other end of this winding to the terminal I64. Hencewhen circuit is closed to the terminals I 62 and l 64 to operate themotor 38, the valve 82 is also opened.

As has been explained, the valves l0 and It must also be opened when theheat exchanger 68 is to serve as a condenser and this is accomplished inthe following manner:

A conductor H69 is connected to the terminal of the winding l5fi whereatthe conductor M9 is connected and this conductor leads to a terminal H0in the pump relay. Another terminal lll is provided in this relay sothat when the armature l52 is attracted the contact H2 may close thecircuit between the terminals llll and HI. A conductor lira leads fromthe terminal ill to a terminal H3 in a thermostat to be described morefully hereinafter. A conductor lld leads from the terminal H3 to one endof the winding N5 of the ice tank. relay and the other end of thiswinding is connected to a conductor lit that is connected to a conductorlll that is connected to conductor ltl. When the winding lib isenergized upon closing of the circuit between the terminals H6 and ill,the armature H8 is attracted. On the armature 578 is a contact l'lllwhich, when the armature is attracted, closes the circuit between theterminals lflll and ESL The terminal ltli is connected by a conductoris? to the conductor 52 3. A conductor ltd leads from the terminal ldlto one end of the winding of the solenoid of the valve l3 and the otherend of this winding is connected to the distributing wire I I8 by aconductor ld. Hence the valve i3 is opened at the same time as that atwhich the valves Al. 59 and 82 are opened.

Another contact NE on the armature H6 closes the circuit between theterminals E86 and it? when said armature is attracted. A conductor itleads from the terminal I86 to a terminal I89. A conductor I96 leadsfrom the terminal its to a terminal l9l. A conductor 592 leads from theterminal lQl to a terminal l93 in the heating relay and circuit from theterminal l93 to another terminal ltd in this relay is normally closed bya contact I95 mounted on the armature of this relay. A conductor lSt isconnected to a terminal l9? from which a conductor W8 leads to theconductor l28. A conductor l99 leads from Y the terminal l8? to one endof the winding 200 of the valve l6 relay, the other terminal of thiswinding being connected to conductor ill by a conductor Ziil. Thus whenthe winding 20B is energized the armature 202 is attracted and thecontact 203 thereon closes circuit between the terminals 254% and 2%. Aconductor 28% connects the terminal 28 to the distributing wire lll. Aconductor 20? leads from the terminal 265 to one end of the winding ofthe solenoid of the valve l0 and the other end of this winding isconnected to the distributing wire M8 by a conductor 288, and when thewinding of the solenoid of valve it is energized this valve is openedalong with the valves Al, 59, 82 and it.

A terminal 209 is provided in the valve it relay and is associated withthe terminal M5. A contact 2N3 closes the circuit between the terminalsI45 and 209. The contact 289 is connected to the distributing wire illby a conductor 2i l. Thus when circuit is closed between the contacts M5and 209, circuit to the winding Hill of the solenoid of valve 59 isclosed, which circuit is in parallel with the circuit to this windingpreviously closed by closing the circuit between the terminals ldl andI42 in the valve ti relay.

Terminals 2l2 and 2l3 are provided in the valve 10 relay and circuitbetween these terminals is closed by a contact Zld when the winding 200is energized. Terminal M2 is connected to the terminal I89 by aconductor 2I6. One terminal of a .thermal relay 2I6 is connected toterminal 2I3 engagement of contact I85 from terminals I86 and I81 in theice tank relay. Thus, breaking of the circuits closed by the valve 10 isdelayed for a short time interval until the thermal relay opens, andthis serves to maintain the valves 59 and 10 open so that the compressorC2 may evacuate refrigerant from the heat exchanger 68.

The circuits thus far described are closed each time the heat exchanger68 is to operate as a condenser. However, when the car is in motion andit is desired to refrigerate air flowing over the heat exchanger 49 andit is not necessary to refrigerate the tank 63, somewhat differentcircuits are closed as follows: When the car is in motion the speedresponsive device S, such as that illustrated in Fig. 18, is operatedand when the device includes a rotor, such as the rotor 95 havingmercury therein, the mercury will first close a circuit between theconductor rings IN and I02, and as the speed increases circuit will beclosed between the conductor rings IOI and I02 and I03.

-When circuit is closed between the conductor rings IOI and I02 and I03,current flows from the terminal I9I through conductor II2 to the contactI09 which bears on conductor ring WI, and when the mercury closes thecircuit between the conductor rings IOI and I03 circuit is closed to thecontact I05 and current flows through the conductor IIO to terminal 2I9in the centrifugal switch relay. Of course, when the circuit is closedto the conductor ring I03 it will have previously been closed toconductor ring I02 and current will flow through contact I01 andconductor I II to terminal 220 which cooperates with terminal 2I9,,,aswill be explained. A conductor 22I leads from terminal 2I9 to'one end ofthe winding 222 of the centrifugal switch relay, and when circuit isclosed to the contact 2 I 9 the winding 222 is energized inasmuch as theother terminal thereof is connected by a conductor 224 to a terminal 225that is connected'to the conductor I3I by a conductor 226. When thewinding 222 is energized, the contact 221 closes the circuit between theterminals 2I9 and 220. It will be noted that circuit is not closed tothe winding 222 until circuit is closed to the conductor ring I03.However, when circuit is closed to the conductor ring I03, the terminal2I9 is connected to the conductor ring I02 by reason of the engagementof contact 221 with terminals 2I9 and 220. Thus the winding 222 is notenergized until a predetermined speed is attained but this winding iskept energized when the speed falls below this predetermined speed andit is not deenergized until there is an appreciable reduction in speedsufllcient to take the conductor ring I02'out of circuit. Hence, theremay be a variation in the speed of operation of the car without aresultant starting and stopping of the mechanisms controlled by thecentrifugal switch relay.

The centrifugal switch relay controls operation of the devices whichsupply refrigerant to the heat exchanger 49. When the winding 222 isenergized, the armature 223 is attracted whereupon the contact I5 I0 isdisengaged from the terminals I5Ia and I5Ib which opens the circuit tothe winding I50 of the pump relay whereupon operation of the motor 38 isinterrupted and the valve 82 is closed. Deenergizing of the winding I50also opens the circuit to the winding I15 of the ice tank relay bydisengaging the contact I12 from the terminals I and HI. Deenergizing ofthe winding I15 disengages the contact I 19 from the terminals I80 andI8I whereupon circuit to the winding of the solenoid of valve 13 isopened and this valve is closed. Deenergizing of the winding I15 alsodisengages contact I85 from terminals I86 and I81 which interrupts flowof current through conductor I99 and would tend to deenergize thewinding 200 of valve 10 relay were it not for the fact that circuit tothis winding is maintained for a short time after contact I85 disengagescontacts I06 and I81 by the thermal relay 2I6. However, when the thermalrelay 2I6 functions to open the circuit to the winding 200, the contact203 disengages the terminals 204 and 205 and opens the circuit to valve10, which valve thereupon closes.

Whenever air flowing over the heat exchanger 49 is to be refrigerated,the thermostat I will be closed and consequently the winding I of valve4I relay will be energized with the result that circuits to thesolenoids of the valves M and 59 will remain closed and these valveswill be open. Further, the centrifugal switch controls operation of thedevices supplying refrigerant to the heat exchanger 49 to refrigerateair flowing over this heat exchanger for when the car is in motion thecontact I5Ic is disengaged from the contacts I5Ia and I5Ib and the pump38 cannot be operated but, as will be explained, the compressor C2 isoperated. Likewise, when the car is at rest circuit is closed to thepump but ..the

circuit controlling the compressor is open.

The compressor C2 is to be operated when the winding 222 is energizedand therefore circuit is closed to the magnetic clutch 25 and this isbrought about in the following manner: A conductor 228 is connected tothe conductor I I2 and leads'to a terminal 229 in the centrifugal switchrelay. Another terminal 230 is provided in this relay and when thewinding 222 is energized the contact 23I closes the circuit between theterminals 229 and 230 whereupon circuit is closed to the winding 232 ofthe magnetic clutch relay through conductor 233 in which the lowpressure switch 234 (Fig. 1) and the high pressure switch 235 (Fig. 1)are provided, these two switches normally being closed. The switch 234opens circuit to the magnetic clutch relay to stop the compressor whenthe suction pressure of the compressor drops to a predetermined minimum,and the switch 235 opens circuit to this relay when the dischargepressure of the compressor reaches a predetermined maximum. The winding232 is also connected to the conductor I11 by a conductor 236 so thatwhen circuit is closed between the contacts 229 and 230 this winding isenergized. When the winding 232 is energized, the armature 231 isattracted and attraction of this armature causes the contact 238 toclose the circuit between the terminals 239 and 240 and the contact 24Ito close the circuit between the terminals 242 and 243. The magneticclutch 25 and the winding of the solenoid of the valve 30 are connectedto the terminals 240 and 243 by conductors 244 and 245, respectively.The terminal 239 is connected to the terminal 246.by a conductor 241 andthe terminal 246 is connected to the distributing wire I I1 by aconductor 248 which is a continuation of the conductor I59. The terminal242 is connected to a terminal 249 by a conductor 250 and the terminal249 is connected to the distributing wire I It by a conductor 25I whichis a continuation of the conductor I60. Thus when the contacts 238 and2M close circuit between their cooperating terminals, the magneticclutch 25 is engaged and the valve 39 is opened.

The foregoing circuits remain closed so long as the thermostat I25 isclosed but if the tem perature of the air affecting this thermostatfalls below the setting of the thermostat it opens and therupon thewinding I30 of the-valve tI relay is deenergized and this :opensthe-circuit to the-solenoids of the valves GI and 59-which.

thereupon close. However, the compressor C2 continues to operate butthis reduces the pressure in the pipe 60, strainer 5| and pipe 62, and

'when a predetermined low pressure is reached in these parts the switch23% operates to open the circuit to the winding 232 of they magneticclutch relay whereupon the magnetic clutch is deenergized as well as thesolenoid of the valve 39 and the clutch is disengaged, interruptingoperation a of the compressor, and the valve 30 is closed.

pipe 62 whereupon the low pressure switch 236 I closes and the winding232 is reenergized to reengage the magnetic clutch 25 and open the valve30.

When it is desired to refrigerate air flowing over the heat exchanger 49and also to refrigerate the tank 63, the relay windings I39 and 232remain energized. However, the ice tank. thermo-.-

state 89 will close at this time and currentis supplied to thisthermostat, when the :caris; in

operation, in the following manner:

A conductor 252 leads from the terminal 229 to the terminal 253 in thecentrifugal switch relay. Another terminal 254 is provided in this relayandwhen the winding 222 is energized a I contact 255 closescircuitbetween the terminals 253 and2-54. Terminal 256 is connected to thethermostat 84 by a conductor 255. .Thus when the thermostat 84 closes,circuit is established through conductor I14 to winding I15 of the icetankrelay whereupon the valves 13 and 10 are opened which, as described,permits refrigerant to circulate through the heat exchanger 58. Aspreviously explained, the energizing of the winding I15 establishesanother circuit to the solenoid of the valve 59 in parallel with thecircuit to this solenoid established through the valve ea relay. Whenthe tank 63 is to be refrigerated but air flowing over the heatexchanger is not to be refrigerated, the thermostat I25 opens whichbreaks the circuit to the winding I39 of the valve GI relay and thisopens circuit to the solenoid of the valve GI and it also opens one ofthe parallel circuits to the valve 59, but this valve remains openinasmuch as the winding I15 of the ice tank relay will be energized byreason of the fact that the thermostat 84 will be closed. Thus only thevalve M is closed which shuts oil flow of refrigerant to the heatexchanger 49 but refrigerant contlnues to flow through the heatexchanger 68 and refrigeratesthe tank 63.

The foregoing description describes the manner in which the controlsoperate when the heatexby this thermostat inoperative.

A conductor 258 1eads from the terminal 251 to a terminal 259 in themagnetic clutch relay. A terminal 259 is provided in this relay andcircuit between these terminals is closed by a contact 26L Thlsarrangement is utilized to keep the compressor 02 operating in event thecompressor .has been supplying refrigerant to the heat ex-' changer'ttso that any refrigerant in this heat exchanger may be returned to thereceiver 3I in event the switch blade I22 is swung from engagement withthe terminal I23 directly into engagement with the terminal 251.Therefore, a conductor 262 leads from the terminal 269 to one end of thewinding 263 of the heating relay. A conductor 26d leads from the otherend of this winding to the conductor I3I. However, if the compressor C2has been operating, the winding 232 will have been energized andtherefore the contact 26I will be disengaged from the contacts 259 and260 with the result that circuit is not closed to the winding 263 assoon as the blade 122 engages the terminal 251. When the blade 622disengages the terminal I23, circuit through conductor I62, terminalI89, contact I19, terminal I8I conductor I93, solenoid of valve 13 andconductor I84 is broken and valve 13 closes so that no more refrigerantis supplied to the evaporator 68. I have already explained that, whenblade I22 disengages contact I23, circuit to the thermostat I25 isinterrupted and that valve 6! is therefore closed. However, the valves59 and 19- remain open and when the winding 232 is energized and thecompressor continues to operate until the pressure'in pipe 60 reaches apredetermined minimum, the low pressure switch 234 opens and breaks thecircuit-to winding 232,

thus deenergizingthe magnetic clutch relay 232,

disengaging the clutch and closing valve 39. This will not occur untilsubstantially all of the refrigerant has been returned to the receiver3I. However, as soon as the winding 232 is deenergized the contact 26Ibridges the terminals 259 and will not occur until the blade I22 isdisengaged from the terminal 251.

In order for vapor from the receiver 3I to circulate to the heatexchanger 49, it is necessary that the valve 85 be opened and this isbrought about as soon as the winding 263 of the heating device relay isenergized. Terminals 266 and 261 are provided in the heating relay and acontact distributing wire I I8. Thus when the contact 268 closes thecircuit between the terminals 268 261, the solenoid of valve 68 isenergized and this valve is opened.

The valve I must also be opened when the heat exchanger 49 is operatingas a heater in order to by-pass the refrigerant about the expansionvalve 43 and to this end terminals 214 and 215are provided in theheating relay, and when the contact 216 closes circuit between theseterminals the winding of the solenoid of valve 5I is energized, currentflowing from conductor 269 through conductor 211, terminal 214, contact218, terminal 215, conductor 218, winding of the solenoid of valve 5I,conductor 219 to conductor 213.

The valve 4I must now be opened to permit the refrigerant by-passedabout the expansion valve 43 to return to the receiver 3I and to thisend a conductor 288 leads from the conductor 269 to a terminal 28I inthe heating relay. When the heating relay is energized, a contact 282closes the circuit between terminal 28I and a terminal 283 to which aconductor 284 is connected that leads to one terminal of the winding ofthe solenoid of valve 4| and the other terminal of this winding isconnected to the conductor I I8 by conductor I39. Closing of thiscircuit opens valve H.

The motor operated valve 89 is also controlled by the heating relay anda pair of terminals 285 and 286 are provided in the relay between whichcircuit is closed by a contact 281 when the winding 263 is energized. Aconductor 288 is connected to the terminal 286 and to one terminal ofthe opening motor 289 of the motor operated valve 89. A conductor 298leads from the other terminal of the motor 289 to the wire I3I. Aconductor 29I is connected to the terminal 285 and to a terminal 292 inthe thermostat 293. A conductor 294 is connected to the terminal 295 inthe thermostat and to a terminal 296 in the heating relay. A conductor291 connects the terminal 296 with the conductor 269. A conductor 298leads from the terminal 299 in the thermostat 293 to a terminal 388. Aconductor 389 leads from the terminal 388 to one terminal of the closingmotor 382 of the motor operated valve 89.

When the winding 263 is energized and the contact 281 closes the circuitbetween the terminals 285 and 286, the motor operated valve 89 is undercontrol of the thermostat 293. The terminal 295 of the thermostat isconnected to the conductor 269 which in turn is connected with thedistributing line II1. When the blade 383 of the thermostat moves intoengagement with the contact 292 circuit is closed through the openingmotor 289 as follows: From terminal 292 through conductor 29I, terminal285, contact 281, terminal286, conductor 288, motor 289, conductor 298to conductor I3I and thence to distributing wire I I8. This operates toopen the valve 89 and admits steam into the coil 81 which occurs whenthe temperature in the car falls below a predetermined minimum. When thetemperature in the car rises above a predetermined maximum, the blade383 moves into engagement withthe terminal 299 and circuit is closedthrough conductor 298, terminal 388, conductor 38l, motor 382 andconductor 298, and this motor then operates to close the valve 89. Itwill be understood that when either the contact 292 or the contact 299is engaged by the blade 383 either the motor 289 or the motor 382 is setin operation. Each motor operates only to open or close the valve,whichever its function may be, and a limit switch in the motor (notshown) breaks the circuit after the function has been performed.

and

When the heating relay 283 is deenergized, it is essential that thevalve 89 be closed and to this end a terminal 384 is provided in therelay which is associated with the terminal 296. when the relay isdeenergized a contact 385 closes circuit between the terminals 296 and384 and current is supplied to the motor 382 as follows: From conductor269 through conductor 291, terminal 296, contact 385, terminal 384,conductor 386, terminal 388, conductor 38l, motor 382, and conductor 298to conductor I3I. and this so operates the motor 382 that the valve 89is closed, the limit switch in the motor interrupting this circuit whenthe valve 89 attains closed position.

When the blade I22 is in the off position, that is, disengaged from boththe terminals I23 and 251, the car heating and cooling devices are bothrendered inoperative but the contact I95 in the heating relay closes thecircuit between the contacts I93 and I94 and energizes those parts ofthe apparatus controlled by the ice tank thermostat 84 so that thecompressor C2 may be operated to supply refrigerant to the heatexchanger 68 to refrigerate the tank 63 when the car is in motion. Ofcourse, when the car is at rest circuit to the magnetic clutch relay isopened by reason of the fact that the centrifugal switch relay will beopened, and therefore even though the ice tank thermostat 84 is closedthe compressor C2 will not be operated but when the car is in motion andthe thermostat 84 is closed the compressor will be operated and the tank63 will be refrigerated.

In event the system shown in Fig. 1 was to be used only forrefrigerating air flowing over the heat exchanger 49, the Icy-pass pipe58 and the valve 5I therein could be eliminated as could the valve 59.Furthermore, the condenser 29 could be directly connected in the pipe 32of the receiver and the valve 38, fitting 33, valve 86 and pipe 85 couldbe omitted and the pipe 55 would be directly connected to the pipe 51thereby elimihating the T-fitting 56. Furthermore, the heating coil 81and its associated parts would be eliminated. The remaining parts wouldbe operated in the manner previously described.

In Fig. 2 an air refrigerating and heating system much like that shownin Fig. l is disclosed. but herein a boiler B is provided instead ofproviding the coil 81 in the receiver 3i. Similar parts in Figs. 1 and 2are numbered identically and the pipe 55 of Fig. 2, like the pipe 55 ofFig. 1, leads to the back pressure valve 53 and the pipe 39 in Fig. 2leads to the T-fitting 48 and has the valve 4! therein. The pipe llleads to T- fitting 12 and the pipe 69 is connected to the heatexchanger 68, and these parts as well as the ice tank 63 are identicalwith similar parts shown in Fig. l.

In the system shown in Fig. 2 a pipe 381 is connected to the dischargeof the pump 31 and has a solenoid valve 388 therein. The pipe 381 isconnected to a T-fitting 389 to which the pipe 39 is connected. A pipeM8 is connected to the fitting 389 and leads to the boiler B. A solenoidvalve 3 is provided in the pipe 3I8 to control flow therethrough. A pipe85a leads from the boiler B to the T-fitting 56 and has the valve 86therein. A liquid level control 3I2 is provided for maintaining a supplyof refrigerant in the boiler B. The steam inlet pipe 86 leads into theheating parts 81a of the boiler B and the pipe 98 leads from these partsand has the trap 9| therein and this pipe and trap function in preciselythe same manner as in the system of Fig. 1.

The system shown in Fig. 2 is operable under all of the conditionspreviously described, that is to say. the system shown in Fig. 2 may beoperated under the Condition G as well as under the other conditions.

Condition A--Fig. 2

When a car is initially placed in service and it is to be cooled, asupply of cracked ice or other refrigerating medium is introduced intothe tank 63 asv was done in the system shown in Fig. 1 and the system ofFig. 2 is arranged as follows: The valves'308, and 4| are opened topermit flow of llquld'refrigerant through the expansion valve 43 intothe heat exchanger 49 as air flowing over the heat exchanger isrefrigerated. Refrigerant vapo'rlzedin'the heat exchanger 49 flows backthrough pipe 52, back pressure valve 53, pipe 55, fltting 58, pipe 51and opened valve 59, fitting 58, :p'ipe fiiland opened valve 10 to theheat exchanger 68, and since the tank is filled with cracked ice thevaporized refrigerant is liquefied as it flows through the heatexchanger 68 and the liquid refrigerant flows through pipe to fitting19. The liquid refrigerant is by-passed about the expansion valve 15through pipe 8| past opened valve 82 and flows to fitting 35 where, asexplained in connection with the system of Fig. 1, it flows eitherthrough the pipe 34 into the receiver 3| or through pipe 36 to the pump31 by which it is forced to the expansion valve 43 and in this system,as in the system of Fig. 1, equilibrium is soon established between theaction of the heat exchangers 49 and 88.

The valves 5|, 30, 86, 89 and 3 are closed under this condition ofoperation.

Condition B-Fiq. 2

When the refrigerating mechanism is to be operated to supply refrigerantonly to the'heat exchanger 49, the valve 4| is opened as well as thevalve 308 and the valve 5| is closed. The valve 59 is opened as well asthe valve 30. The valves 5|, 10, 89, 86, I3, 82 and 3 are closed.

With the valves arranged in this manner refrigerant may flow from thereceiver 3| through opened valves 308 and 4| into the heat exchanger 49under the control of the expansion valve 43 which operates in the usualway to control refrigeration in the heat exchanger. erant returnsthrough opened valve 59 to the compressor C2 from whence it flowsthrough the condenser 29 and past opened valve 30 into the receiver 3i.The heat exchanger 88 is isolated from the system because the valves 13and 10 are closed and no refrigerant flows into the boiler 13 becausethe valve 3| is closed.

Condition CFig. 2

When the refrigerating mechanism is to be operated not only to supplyrefrigerant to the heat exchanger 49 but also to the heat exchanger 88so as to freeze water in the tank 83, the valves l0 and 73 are opened inaddition to the valves which are opened under Condition B, the othervalves closed under Condition B remaining closed. Therefore,refrigeration is effected in the heat exchanger 88 as well as in theheat exchanger 49.

Condition 11-1 111. 2

When refrigerant is to be supplied to the heat exchanger 68 but not tothe heat exchanger 49, the valves 308 and 4| are closed as well as thevalve 5| and this shuts ofi the supply of liquid refrigerant to the heatexchanger 49. The other The refrigvalves are arranged as underConditions B and C and refrigerant is circulated only through the heatexchanger 89.

- Condition E-Fia. 2

When the car stops ormoves so slowly that operation of the compressor C2is interrupted and refrigeration of air flow over the heat ex-v changer49 is to be continued, the ice stored in the tank 83 is utilized tocondense the refrigerant vaporized in the heat exchanger 49 and thesystem is operated the same as it is operated under Condition A.

Condition ,E- -Fig. 2

When the heat exchanger-49 isto function as a heater the system isarranged as follows: .Valve 89 is operated by a thermostat responsivetothe temperature of air leaving, the heat exchanger and steam or otherheating medium is supplied to the heating parts of the boiler B whichvaporizes refrigerant supplied to the boiler through the pipe 3|0 pastopened valve 3| I. The vapor.- ized refrigerant flows through pipe 85apast opened valve 88, fitting 56, pipe 55, back pressure solenoid of thevalve 308 and towthe motor 38' whereupon the pump 31 is operated towithdraw liquid from the receiver 3| and force it into the boiler B.

The valves30, 59, I0, 13 and 82 are In event the refrigerant level toohigh in the boiler B, the liquid level control 3|2 again operates butunder this condition of operation only the solenoid of the valve'308 isenergized, and when this valve opens liquid refrigerant drains from theboiler B back into. the receiver 3| since the boiler is mounted at ahigher level than the receiver.

Condition G--Fig.2

In event a car equipped with the system shown in Fig. 2 is to be runfrom a cold climate into a warm climate, it is desirable to accumulateenergy so that when the car enters the warm climate refrigeration of airflowing over the heat exchanger 49 may be immediately effected even ifthe car is at rest, and it is desirable under these conditions tooperate the system to supply vaporized refrigerant to the heat exchanger49 as under Condition F and to supply liquid refrigerant to the heatexchanger 68 as under Condition D and to this end the valves arearranged as under Condition F except that the valves 30, i0 and 13 areopened.

The compressor C2 is set in operation and vaporized refrigerant iswithdrawn from the heat exchanger 68 through pipe 89 past opened valve70 to the fitting 58, closed valve 59 preventing flow through the pipe51. From the fitting 58 the refrigerant returns to the compressor C2from whence it is discharged into the condenser 29 and refrigerantliquefied in the condenser flows into the receiver 3|. The valve 308remains closed except when refrigerant is to be supplied to or withdrawnfrom the boiler B as under Condition F, but since this functioning ofthe valve 308 will rarely be necessary satisfactory operation of bothheating the car and refrigerating the tank 83 may be carried outsimultaneously.

In event the system shown in Fig. 2 is to be used only for refrigeratingair flowing over the heat exchanger 49, the boiler B could be eliminatedand, of course, the means for supplying heat thereto and the pipe 850'and the valve 88 could be eliminated and an elbow would be substitutedfor the T-fitting 56. Furthermore, the pipe 3H! and the valve 3 thereinas well as the fitting 309 and the valve 308 could be eliminated and inthis event the pipe 39 would be directly connected to the pump 31 as inFig. 1. A control system such as that shown in Fig. 17 can be providedfor the system shown in Fig. 2 or, as explained in connection with thesystem of Fig. 1, another type of control system may be used. Byreferring to the system shown in Fig. 17, I believe it will be apparentthat by the use of relays such as those disclosed therein the describedoperation of the valves of the system of Fig. 2 under the variousconditions of operation can be brought about automatically as is done bythe control system of Fig. 17.

The form of air refrigerating and heating system shown in Fig. 4 is muchlike that shown in Figs. 1 and 2 but in place of providing a heatingcoil in the receiver as is done in the system of Fig. 1 or a boiler B asis done in the system of Fig. 2 the ice tank is utilized as a means forvaporizing the refrigerant for heating purposes. This system like thesystem of Fig. 1 cannot operate under Condition G.

In Fig. 4 the pipe 95 and the valve 86 are omitted inasmuch as the pipe69a serves in this instance to supply vaporized refrigerant for heatingpurposes to the pipe 55.

A solenoid valve M3 is provided in the pipe 360. which interconnects thefitting 35 with the pump 31. Furthermore, a pipe 30! leads from the pump31, as in the system of Fig. 2, to a fitting 309. The pipe 39 isconnected to the fitting 309 and leads to the expansion valve 43 and hasvalves 4i and 308a therein. A pipe 3i0a leads from the fitting 309 to afitting 3M and has a valve 3| Ia therein. A pipe 80a leads from thefitting I9 to the fitting 3M. A pipe 3E5 connects the fitting 3!! to theheat exchanger 68 in the tank 53a. The pipe 69a leads from the heatexchanger 68 to a fitting 56a to which the pipe 55 is connected, and thevalve Hi is provided in the pipe 69a. A pipe 50a leads from the fitting59a to the strainer (ii for in this form of the invention the fitting 58and the pipe 60 are not required. The valve 59 is provided in the pipe50a.

The steam supply pipe 88 having the temperature responsive valve 89therein leads directly into the tank 63a and a pipe 99a leads from thetank 63 and affords a steam discharge, this pipe having the usual steamtrap 9| therein. However, a solenoid valve 3I6 is provided in the pipe90a. ahead of the steam trap 9i. The water supply pipe 64 leads into thetank 63a and has a solenoid valve a therein. A liquid level control 3l2ais provided in association with the tank 63a and is connected to thefitting 3H and a fitting 3|! in the pipe 69a. adjacent the heatexchanger 58.

The operation of the system shown in Fig. 4

under the various conditions of operation is as follows:

Condition 4-Fig. 4

The solenoid valve. M5 is opened to drain water from the tank 53a andafterthe tank is drained this valve is closed. The tank 33a is thenfilled with cracked ice as under Condition A in the systems shown inFigs. 1 and 2.

Liquid refrigerant admitted into the heat exchanger 49 under control ofthe expansion valve 43 is vaporized in the heat exchanger 49 and flowsback through pipe 52, back pressure valve 53 and pipe 55 to fitting 58a.Valve 59 is closed so that the vaporized refrigerant is prevented fromflowing through the pipe 500 to the compressor C2. However, the valve 10is opened and the refrigerant flows through pipe 69a to the heatexchanger 58 wherein it is liquefied. The liquid refrigerant flowsthrough pipe 3I5 to fitting 3 but flow through pipe 3l0a is prevented byclosed valve 3lla. From fitting 3| 4 the liquid refrigerant flowsthrough pipe 89a to fitting 19 and it is then by-passed about theexpansion valve 15 through pipe 8| past opened valve 82 to fitting 12from whence it flows through pipe H past opened valve 13 to the fitting35.v The liquid refrigerant may return to the receiver 3| through pipe34 or it will flow through pipe 36a past opened valve 3l3 to the pump31, the refrigerant dividing at fitting 35 in the manner set forth morefully in the description of the system shown in Fig. 1 when operatingunder Condition A. Liquid refrigerant flowing to the pump 31 is forcedby the pump through pipe 351, fitting 309 and through pipe 39 toexpansion valve 43 past opened valves 308a and 4|. In addition to thevalves 59 and. 3| la, the valves 5!, 30, 89, 65a and 3l 6 are closedunder this condition of operation.

Condition B--Fig. 4

When refrigerant is to be supplied only to the heat exchanger 49, thevalves 3l3, 308a and ii are opened so that liquid refrigerant may flowfrom the receiver 3! to the heat exchanger 19 under control of theexpansion valve 43. Refrigerant vaporized in the heat exchanger 89 isreturned through pipe 52, back pressure .valve 53 and pipe 55 to fitting56a. The valve 10 is closed so that the vaporized refrigerant isprevented from flowing through pipe 69a but valve 59 is open so that therefrigerant can be drawn through the pipe 9012 by the compressor C2.Compressor C2 forces the refrigerant to the condenser 29 and past theopened valve 39 into the receiver 3i. The valves 5!, I3, 82 and Bi laare closed so that liquid refrigerant cannot flow to the heat exchanger68, and the valves 89, 95a and 3l6 are also closed.

Condition CFig. 4

When refrigerant is to be supplied to the heat exchanger 68 to freezewater in the tank 63a, it is first ascertained whether or not there is asufficient supply of water in the tank and if not the valve 65a isopened to fill the tank 63a up to the level of the overflow device 56.Then the valves which were opened under Condition B are opened and alsothe valves I3 and 10 are opened so that liquid refrigerant may flow tothe heat exchanger 68 through the opened valve 73 under control of theexpansion valve 15 and so that refrigerant vaporized in the heatexchanger 58 may be returned through. the pipe 69a past opened valve 10to the fitting 56a from whence the refrigerant is drawn through pipe 60aby the compressor C2. The valves other than the valves 13 and ill whichwere closed when the system shown in Fig. 4 was operating underCondition B remain closed when the system is operated under Condition C.

Condition DFig. 4

When liquid refrigerant is to be supplied only to the heat exchanger 69,the valves 308a and 4i are closed. The other valves are arranged in thesame manner as the valves are arranged when the system is operatingunder Condition C, and since the supply of liquid refrigerant to theheat exchanger 49 is shut off by closing the valves 308a and 4i, liquidrefrigerant is supplied only to the heat exchanger 68.

Condition EFig. 4

When the car stops or moves so slowly that operation of the compressorC2 is interrupted and refrigeration of air flow over the heat exchanger49 is to be continued, the ice stored in the tank 63 is utilized tocondense the refrigerant vaporized in the heat exchanger 49 and thesystem is operated the same as it is operated under Condition A.

Condition F-Fig. 4

When the system shown in Fig. 4 is to he operated to supply vaporizedrefrigerant to the heat exchanger 49 for the purpose of heating airflowing over this heat .exchanger, the valves 59, 30, 3i3, i3 and 82 areclosed. The valves 10, El, 3080. and 3| la are opened. The temperatureresponsive valve 89v operates to supply steam, as required, into thetank 63a and the valve 3? operates to permit water accumulated in thetank 53 to be discharged therefrom. The valve 65a remains closed at thistime to shut ofi water from the tank 63a. Steam admitted into the tank63a vaporizes the refrigerant in the heat exchanger 68 and this heatedfluid circulates through the heat exchanger 49 to heat air flowing overthis heat exchanger, and in event the liquid level in the heat exchanger68 falls the liquid level device 3i2a operates to open the valve 3i3 andstart the motor 38 so that the pump 31 v may withdraw refrigerant fromthe receiver 3i through pipe 34, fitting 35 and pipe 36a and the liquidrefrigerant so withdrawn isforced through pipe 391, fitting 309, pipe3iila, fitting 3M, pipe 3i 5 to the heat exchanger 68. If the liquidrefrigerant in the heat exchanger rises, the liquid level device 3i2a orthe like opens the valve 3i 3 so that the liquid may drain back into thereceiver 3i inasmuch as the tank 63a is mounted at a higher level thanthe receiver 3i.

If the system shown in Fig. 4 was to be used only for refrigerating airflowing over the heat exchanger 49, the valves 5i, 59, 308a, 3i3 and'3iia. could be eliminated as wellas pipe sum and the fittings providedfor connecting this pipe. Moreover, a manual valve could be used inplace of the solenoid valve 65a.

In Figs. 5, 6, 9 and a multi-cylinder compressor C3 'is illustratedwhich can be substituted for the compressor C2 in the systemsillustrated in Figs. 1, 2 and 4. If this substitution is'made it is notnecessary to change the connections to the high pressure side of thecompressor for insofar as the high pressure connections are concernedthe compressors are interchangeable. However, the low pressureconnections of the compressors must be changed in the manner now to bedescribed.

When the compressor C9 is substituted for the compressor C2 in thesystem shown in Fig. 1, the low pressure or suction connections are madeas shown in Fig. 5. The pipe 60b is-connected to the fitting 56 insteadof the 'pipe 51 and this pipe 60b leads to a strainer Bia similar to thestrainer ii. The valve 59 is provided in the pipe 60b. The pipe 85 leadsto the T-fitting 33 just as is done in Fig. 1. The pipe 62a leads fromthe strainer 6la to a solenoid valve 3! and fittings 3i9 are provided inthe pipe 620. to which the inlets 320 (Fig. 6) to the first threecylinders of the compressor C3 are respectively connected.

The pipe 69 leads from the heat exchanger 69 to a coupling 32i to whicha pipe 600 is connected that leads to a strainer Gib. A pipe 62b leadsfrom the strainer Bib to the solenoid valve 3! and a fitting 3i9a isprovided therein to which the inlet 320a of the fourth cylinder of thecompressor is connected.

When the compressor C3 is substituted for the compressor C2 in thesystem shown in Fig. 2, the high pressure connections of the compressorare the same as shown in Fig. 2 but the pipe 60b is connected to thefitting 56 and the valve 59 is provided therein. The pipe 69 again leadsfrom the heat exchanger 68 to the coupling 32i and the pipe 500 leadsfrom the coupling 32i to the strainer Gib. The connections between thestrainers Sid and Gib are the same as in Fig. 5. In this instance thepipe 55a is connectedto the boiler B just as this pipe is connected inthe system shown in Fig. 2.

When the compressor C3 is substituted for the compressor C2 in thesystem shown in Fig. 4, the high pressure connections are the same asthose described for the-system shown in Fig. 4. However, the lowpressure connections are made as shown in Fig. 10, that is to say, thepipe 60b is connected to the fitting 56a and the valve 59 is providedtherein. The pipe 69a in this instance leads from the heat exchanger 68'and is connected to the fitting 56a and the valve 10a is providedtherein. Furthermore, a T-fitting 322 is provided in the pipe 69a andthe pipe 600 is connected to this T-fitting 322 and leads to thestrainer Gib. A solenoid valve 323 is provided in the pipe 600 in thisinstance. The connections between the strainers Bio. and Gib are thesame as those provided in the arrangement of Fig. 5. s

The multiple cylinder compressor shown in Figs. 5, 9 and 10 operatesubstantially the same as the compressors shown in Figs. 1, 2 and 4under the various conditions of operation. All of the various valves inthe systems shown in Figs.

1, 2 and 4 operate under the various-conditions of operation in the samemanner as that which has been described except the valves 59 and i0.

- Furthermore, when the multiple cylinder com- Condition A-Multz'plecylinder compressor When the compressor C3 is used in the system of Fig.1 in the manner shown in Fig. 5, the valve 59 is open under Condition Aand vaporized refrigerant leads through pipe 55 past opened valve 59 andthrough pipe 60b to the strainer Na and thence through pipe 62a, openedsolenoid pling 32l and through pipe 69 past opened valve Likewise, whenthe compressor C3 is substituted for the compressor C2 in the systemshown in Fig. 2, vaporized refrigerant returns through pipe to fitting56 from whence it fiows through pipe past opened, valve 59, throughstrainer 6la, pipe 62a, opened valve 3l8, pipe 62b, strainer 6lb, pipe600, coupling 32l and through pipe 69 past opened valve 10.

When the compressor C3 is substituted for the compressor C2 in thesystem shown in Fig. 4, vapor refrigerant returning through pipe 55under Condition A flows to fitting 56a but preferably the valve 59 isclosed as well as the valves 3|8 and 10 but the vaporized refrigerantmay return to the heat exchanger 68 through pipe 69a by opening valve323.

Condition B-Multiple cylinder compressor 56a and through pipes 60b pastopened valves 59 and into the pipe 62a and 62b. In the system as shownin Fig. 10 the valve 323 will be closed under this condition ofoperation.

Condition C-Multiple cylinder compressor When the multiple cylindercompressor C3 is substituted for the compressor C2 used in the systemsshown in Figs. 1, 2 and 4, the operation of the compressor C3 is quitedifierent from the operation of the compressor C2, for the first threecylinders of the compressor C3 withdraw vaporized refrigerant from theheat exchanger 49 while the fourth cylinder of the compressor withdrawsvaporized refrigerant from the heat exchanger 68.

Therefore, in the systems as shown in Figs. 5, 9 and 10 both the valves59 and Ill are opened but the valves 3|8 are closed. Under thiscondition of operation the valve 323 shown in Fig. 10 is closed.

Then in the system shown in Fig. 5 vaporized refrigerant from the heatexchanger 49 flows through pipe 55, fitting 56, past opened valve 59 toflow through the inlets 320 and refrigerant from the heat exchanger 68fiows through pipe 69 past opened valve 16 into pipe 60c and through theinlet 320a.

In the system shown in Fig. 9, vaporized reirigerant returns from theheat exchanger 49 through pipe 55 past opened valve 59 to fiow through;the inlets 326, and refrigerant from the heat exchanger 68 flows throughpipe 69 past opened valve 10 to the inlet 320a.

In the system shown in Fig. 10, vaporized refrigerant returns throughpipe 55 past opened valve 59 to the inlets 326 and refrigerant from theheat exchanger 68 flows through pipe 69a to T-fitting 322 from whence itflows through pipe 600 past opened valve 10 to the inlet 326a.

It will be noted that it is imperative that the valve 3l8 remain closedduring this condition of operation. Furthermore, when a multiplecylinder compressor is used in the manner shown in Figs. 5, 9 and 10,the back pressure valve 53 may be eliminated because the first threecylinders of the compressor withdraw thermic fluid from the heatexchanger 49: while the fourth cylinder withdraws thermic fluid from theheat exchanger 68, and since these heat exchangers are subjected toindependent suction eflects there will be no tendency to equalize thesaturation pressures therein.

condition D-Multiple cylinder compressor -as shown in Figs. 5, 9 and 10.However, the

valves 10 are opened in the systems shown in these three figures so thatrefrigerant returning from the heat exchanger 68 may be drawn into thecompressor and in this instance the valves 3|8 are opened so that therefrigerant is not only drawn through the inlet 320a but also throughthe inlets 320. The valve 323 in the system shown in Fig. 10 is, ofcourse, closed at this time.

Condition E-Multiple cylinder compressor When the systems shown in Figs.1, 2 and 3 include the compressor C3 in place of the compressor C2, thesystems operate precisely as described under Condition A, multiplecylinder compressor.

Condition F-Multiple cylinder compressor When the system as shown inFig. 5 is included in the system shown in Fig. l and this system isoperated for heating, the valves 59, 3 l8 and 10 are closed andvaporized refrigerant flows from the receiver 3| through the pipe 32 tofitting 33 past opened valve 86 into pipe 85 to fitting 56 and thencethrough pipe 5, the remainder of the operation being the same asdescribed under Condition F, Fig. 1.

When the system shown in Fig. 9 is included in the system shown in Fig.2, the valves 59, 3i6 and 10 are closed and vaporized refrigerant flowsfrom the boiler B into the pipe 85a past opened valve 66,to fitting 56and thence through pipe 55, and the remainder of the system operates asdescribed under Condition F, Fig. 2.

When the system shown in Fig. 10 is included in the system shown in Fig.4, the valves 59, 3l8 and 10 are closed so that vaporized refrigerantflowing through the pipe 69a may fiow past opened valve 923 to fitting56a from whence the vaporized refrigerant flows through pipe 55, and thesystem operates as described under Condition F, Fig. 4.

Condition GMultiple cylinder compressor Only the system shown in Fig. 9can be used to accomplish this condition and the system shown in Fig. 9is incorporated in the system shown in Fig. 2 for this purpose. Underthis condition of operation since vaporized refrigerant is to flowthrough thhe pipe 85a. from the boiler B, the valve 86 is opened and thevaporized refrigerant flows into the pipe 55. However, the valve 59 isclosed but the valves 318 and 16 are opened and the vaporizedrefrigerant returning from the heat exchanger 68 through pipe 69 cantherefore flow through the inlets 326 as well as the inlet 320a. Theremainder of this system operates precisely as described under ConditionG, Fig. 2.

In Figs. 7, 8, 11 and 12 a multiple efl'ect compressor C4 is shown whichcan be substituted for the compressor C2 in the systems shown in Figs.1, 2 and 4 in the same manner as that in which the compressor G3 wassubstituted for these compressors. This multiple efiect compressor hasstrainers Bio and Bid associated therewith which correspond to thestrainers Ma and Slb provided on the compressor C3. However, in thisinstance the pipe 62d leads from the strainer Sid to a T-fitting 323provided in the pipe 620 which leads from the strainer Sic. A T-fitting325 is provided in the pipe 62d and the inlet 326 of the compressor C3leading from the crank case of the compressor is connected to thisT-fitting. A solenoid valve 3l8a, similar to solenoid valve M8, isprovided in the pipe 32d between the T-fittings 323 and 325. The pipes62c have fittings 32l'therein to which the inlets 328 of the compressorsC3 are connected and these inlets communicate with the cylinders abovethe lowermost position of the pistons P of the compressors C3. Theskirts of the pistons P are of suficient length that when the pistonsattain their uppermost positions they close ofi the inlets 328 so thatthere is nocommunication between these inlets and the crank cases of thecompressors. J

The temperature maintained in the heat exchanger 43 is considerablyhigher than that maintained in the heat exchanger 68 when these heatexchangers are serving as evaporators. Hence, the saturation pressure inthe heat exchanger 69 is much higher than in the heat exchanger B8. Avalve V is provided in the head of the piston P, and when this pistonstarts downwardly from its uppermost position the pressure ofrefrigerant in the crank case of the compressor which is, suppliedthereto from the heat exchanger 68 opens the valve V and the lowpressure refrigerant in the crank case of the compressor is thereforeadmitted into the cylinder above piston-P. However, just prior to thetime the piston reaches its lowermost position the inlet 328 isdisclosed. Refrigerant is supplied to the inlet 328 from the heatexchanger 39 and this refrigerant is at a much higher pressure than thatwhich is in the crank case and therefore as soon as the inlet 328 isdisclosed this high pressure refrigerant rushes into the cylinder abovethe piston P, closing the valve V, and thereafter the piston P starts toascend and compresses the gas confined in the cylinder thereabove whichis discharged through the pipe 28.

By a comparisonof Figs. 7, l1 and 12 with Figs. 9, l0 and 11 it will benoted that the pipe connections to the compressors C3 and the valvesarranged therein are the same as the pipe connections and the valvestherein to the compressors C3. Therefore, under the various conditionsof operation the systems shown in Figs. '7, 11 and 12 are connectedprecisely in the manner described for the systems shown in Figs. 5, 9and 10. Moreover, as explained in connection with the multiple cylindercompressor, the back pressure valve 53 may be eliminated when a multipleefi'ect compressor is used.

The form of the invention illustrated in Figs. 13, 14 and 15 operatesunder the well-known Kelvin reverse cycle refrigeration principle whenthe heat exchanger 49 is to be used as a heater but otherwise operatesas an ordinary refrigen ating mechanism. In the form of the inventionshown in Fig. 13, a compressor of the usual type such as the compressorC2 is employed. In

heat exchanger 29a, which outlet leads to a ifitting 333. The pipe 3335leads from the T-fitting 334 to a T-fitting 336 and has a solenoid valve337 therein. A pipe 33! leads from the T-fitting 336 to an expansionvalve 338 and a pipe. 333 interconnects the expansion valve and the T-fitting 336. A pipe 330 leads from the T-fitting 336 into a receiver cm.Pipe 33a. leads from the receiver 3m to a T-fitting 35a. A pipe 360leads from the T-fitting 35 to the pump 31a which is operated by a motor38a. The pipe 39 is connected to the discharge of the pump 31a to theexpansion valve 43 and this part of the apparatus is arranged in themanner illustrated in Fig. l. The pipe leads to a. T-fitting 56c and apipe 33! leads from the fitting 560 to a three-way valve 342. A pipe 333leads from the fitting 332 to a strainer 333. Another pipe 335 connectsthe strainer 333 with the three-way valve 332. A pipe 333 connects theT-fitting 330 with the threeway valve 342. The pipe 690 having thesolenoid valve 700 therein, leads from the fitting 530 to a heatexchanger 680 in the ice tank 630. The inlet pipe 800. from the heatexchanger 68c leads to a T-fitting 19a. A pipe 18a leads from thefitting 79a to an expansion valve 130. and a pip Ma leads from theexpansion valve 15a to a T- fitting 12a. A dehydrator Ha and-a strainer16a are provided in the pipe Ma. A pipe 8la interconnects the T-fittings19a and-32a 'and'has a solenoid Valve 82a therein. A pipe Ha leads fromthe T-fitting 12a to the T-fitting 35a and has a solenoid valve I3therein.

The system shown in Fig. 13 operates under the various conditions ofoperation as follows:

Condition A-Fig. 13

The ice tank 630 is filled with cracked ice and the valves 34?, 30a andEl are closed. Refrigerant vaporized in the heat exchanger 43 returnsthrough pipe 55 past opened valve 100 through pipe 690 to heat exchanger680 where it is condensed, and liquid refrigerant flows through pipe 80ato fitting 79a from whence it is by-passed about the expansion valve 75apast opened valve 82a. From fitting 720, the refrigerant may flowthrough pipe i la past opened valve 130. to fitting 35a whereat itdivides to either fiow through the pipe 34a. or pipe 36a, andrefrigerant flowing through the pipe 36a flows through the pump 310.into the pipe 39 from whence it flows to the heat exchanger 39 undercontrol of the expansion valve 43. The division of the refrigerant atthe fitting 35a corresponds to the division at the fitting 35 asdescribed under Condition A, Fig. 1.

Condition B-Fig. 13

